The data sheet indicates that max voltage is -0.3v to 3.6v @ the SDI pins, we typically have transients, in the past I have added low cap. TVS and/or current limiting resistors to mitigate the transients. The DS lists a 1.3k input imped. and ESD protection. Could you let me know if an +/-8-10v 70uS pulse would harm the device? On other devices if you limit the current to <10-15mA the ESD diodes would be able to handle the transient.
Thanks,
Larry